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arXiv 2002.10181cs.IRcs.DB
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图数据上的松弛关系映射

Relaxing Relationship Queries on Graph Data

Shuxin Li, Gong Cheng, Chengkai Li

摘要:

在许多领域中,我们都看到需要在大型实体关系图中搜索查询中指定的一组实体之间的直接和间接关系。被称为语义关联(SA)的搜索结果通常是紧凑的(例如,直径受限的)连通子图,其包含所有查询实体。对于SA搜索的这个问题,存在有效的算法,但是如果一些查询实体在图中距离较远,则将返回空结果。为了减少失败查询的发生,并提供替代结果,我们研究了SA搜索的上下文中的查询松弛问题。简单地放松紧凑性约束将牺牲SA的紧凑性,更重要的是,可能导致性能问题并且是不切实际的。相反,我们专注于从原始失败的查询中删除最小数量的实体,以形成最大成功的子查询,从而最大限度地减少松弛引起的结果质量损失。我们证明,验证子查询的成功变成找到一个实体(称为证书),满足基于距离的查询实体的条件。为了有效地找到一个最大的子查询的成功证书,我们提出了一个最好的优先搜索算法,利用基于距离的估计,有效地修剪搜索空间。我们通过增加两个细粒度的算法来进一步提高其性能:一个基于度,另一个基于距离。广泛的实验上流行的RDF数据集证明了我们的算法的效率,这是更可扩展性比基线。

英文摘要:

In many domains we have witnessed the need to search a large entity-relation graph for direct and indirect relationships between a set of entities specified in a query. A search result, called a semantic association (SA), is typically a compact (e.g., diameter-constrained) connected subgraph containing all the query entities. For this problem of SA search, efficient algorithms exist but will return empty results if some query entities are distant in the graph. To reduce the occurrence of failing query and provide alternative results, we study the problem of query relaxation in the context of SA search. Simply relaxing the compactness constraint will sacrifice the compactness of an SA, and more importantly, may lead to performance issues and be impracticable. Instead, we focus on removing the smallest number of entities from the original failing query, to form a maximum successful sub-query which minimizes the loss of result quality caused by relaxation. We prove that verifying the success of a sub-query turns into finding an entity (called a certificate) that satisfies a distance-based condition about the query entities. To efficiently find a certificate of the success of a maximum sub-query, we propose a best-first search algorithm that leverages distance-based estimation to effectively prune the search space. We further improve its performance by adding two fine-grained heuristics: one based on degree and the other based on distance. Extensive experiments over popular RDF datasets demonstrate the efficiency of our algorithm, which is more scalable than baselines.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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